[The effect of hydroxycamptothecin and topotecan to SKOV3 and CAOV3 in vitro]

To examine the effect of hydroxycamptothecin (HCPT) and topotecan, two kinds of derivative of camptothecin, to two ovarian cancer cell lines, SKOV3 and CAOV3.

Methyl thiazolyl tetrazolium (MTT) was used to establish the dose-effect curves. The ability of these two drugs to induce apoptosis of the two cell lines was determined by the method of terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and DNA Ladder. The morphological changes of the cells were observed by electronic microscope. Expression of c-myc, bcl-2, and fas was estimated by the immunohistochemical staining.

The inhibition of HCPT and topotecan to the growth of SKOV3 and CAOV3 was dose-dependent. 50% inhibiting concentration (IC50) of HCPT and topotecan to SKOV3 was 72 ng/ml and 160 ng/ml, respectively; IC10 of HCPT and topotecan to CAOV3 was 141 ng/ml and 12 ng/ml, respectively. The inhibition of HCPT and topotecan to clone forming rate of two cell lines was significant. The growing curves of SKOV3 and CAOV3 treated by HCPT and topotecan were significantly lower than controls. HCPT and topotecan of 5 ng/ml can elongate the double time of SKOV3 for 49.00 and 1.75 times, respectively. They can elongate the double time of CAOV3 for 2.77 and 1.94 times, respectively. After treated by HCPT or topotecan, SKOV3 generated DNA Ladder. Positive rates of TUNEL of SKOV3 and CAOV3 were elevated by HCPT and topotecan notably. HCPT and topotecan did not affect the expression of c-myc, bcl-2, fas of SKOV3 and CAOV3. Observed by electronic microscope, heterochromatin of SKOV3 and CAOV3 coagulated after treated by HCPT. Micro villi of SKOV3 and CAOV3 were damaged, and some vacuoles appeared in the cytoplasm.

HCPT and topotecan can inhibit growth of SKOV3 and CAOV3 significantly. HCPT and topotecan can induce apoptosis of SKOV3 and CAOV3.